title: Cascades of Sigma factors.
mesh_terms: D001412:Bacillus subtilis / Q000235:genetics; D001435:Bacteriophages / Q000235:genetics / Q000254:growth & development; D005075:Biological Evolution; D005786:Gene Expression Regulation; D009876:Operon; D012808:Sigma Factor / Q000502:physiology*; D013171:Spores, Bacterial / Q000502:physiology; D014157:Transcription Factors / Q000502:physiology*
chemical_list: D012808:Sigma Factor; D014157:Transcription Factors